tonegen32b.s

Mplab C30编译器

;*********************************************************************
;                                                                    *
;                       Software License Agreement                   *
;                                                                    *
;   The software supplied herewith by Microchip Technology           *
;   Incorporated (the "Company") for its dsPIC controller            *
;   is intended and supplied to you, the Company's customer,         *
;   for use solely and exclusively on Microchip dsPIC                *
;   products. The software is owned by the Company and/or its        *
;   supplier, and is protected under applicable copyright laws. All  *
;   rights are reserved. Any use in violation of the foregoing       *
;   restrictions may subject the user to criminal sanctions under    *
;   applicable laws, as well as to civil liability for the breach of *
;   the terms and conditions of this license.                        *
;                                                                    *
;   THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION.  NO           *
;   WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING,    *
;   BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND    *
;   FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE     *
;   COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,  *
;   INCIDENTAL OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.  *
;                                                                    *
;   (c) Copyright 2007 Microchip Technology, All rights reserved.    *
;*********************************************************************


	; Local inclusions.
	.nolist
	.include	"dspcommon.inc"		; MODCON, XBREV
	.list

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	.section .libdsp, code
	
	.global _toneGen32b

	.equ	TF_FFT_SIZE,1024			; 10stage, 1024 point complex FFT

	.text

;............................................................................
_toneGen32b:
;............................................................................
; Context Save
			PUSH	CORCON
			PUSH	PSVPAG
			LNK     #20
;............................................................................

;............................................................................
;;	PSVPAG = __builtin_psvpage(&twiddleFactor);
;;	CORCONbits.PSV = 1;	
			MOV		w4,PSVPAG
			BSET	CORCON,#2
 
			MOV		#4,w4
			MUL.UU	w4,w1,w4				; 4*tone
			MUL.UU	w4,w0,w4				; 4*tone*sample
			SL		w2,#2,w1				; 2*phase
			ADD		w4,w1,w4

			MOV		#(TF_FFT_SIZE*2),w6
			DEC		w6,w6	
			AND		w6,w4,w7
		

			MOV		#ACCAL,w5
			ADD		w7,w3,w7
			LAC		[++w7],A
			MOV		[--w7],[w5]
	


			INC		w6,w6
			AND 	w6,w4,w6

			BRA		nz,NEG_VAL
			BRA		EXIT			


NEG_VAL:
			NEG		A


EXIT:
			MOV		[w5++],w0
			MOV		[w5],w1
;............................................................................
; Context Restore
			ULNK
			POP		PSVPAG
			POP		CORCON
;............................................................................
			RETURN